HIV/AIDS continues to affect the Latino community disproportionately, with more than 200,000 cases in the US attributed to this population. Puerto Ricans are US citizens residing in the Caribbean Island and are a significant part of the growing epidemic among Latinos. Due in part to social stigma, Male-to-Female Transgenders (MTF-TG) constitutes an invisible and underserved group in general, and particularly among Latino communities. Nationally, the proportion of MTF-TG infected with HIV is increasing, as evidenced by the growth from 3% to 8% in new reported cases per year. Extensive research demonstrates that MTF-TG are highly stigmatized and often overlooked in research, interventions, and services. Stigmatization of MTF-TG may have serious health implications given the fact that studies in other contexts have demonstrated that a significant proportion of MTF-TG are infected with HIV, use substances, engage in high risk sexual behaviors, and are not reached by existing health services. The emerging literature on TG health has emphasized the need to focus research and interventions on physicians, many of which have received little training on these issues and may therefore lack the knowledge, experience, and sensitivity to provide quality health care. In addition, the literature emphasizes that a lack of access to quality health care resources can have compounded negative effects on MTF-TG by: decreasing their probability of accessing such services; reducing their access to knowledge about health and HIV prevention; and increasing their perceived stigmatization and marginalization through the medical encounter. These factors highlight the need to focus research on transgender health issues, emphasizing research contributing to interventions to improve access to quality health care for MTF-TG. In order to address this gap we propose a study with the following aims: 1. Explore qualitatively four areas of physician treatment of MTF-TG among a sample of professional physicians in Puerto Rico: (1) physician knowledge of MTF-TG health; (2) competency in treating MTF-TG; (3) willingness to provide services to MTF-TG; (4) and attitudes toward MTF-TG. 2. Document quantitatively the relationship between the stigmatization of MTF-TG (i.e., negative attitudes or behaviors toward MTF-TG) and areas 1-4 identified in Aim 1 (i.e., knowledge, competency, willingness, and attitudes). 3. Identify key intervention targets and strategies to be prioritized for an effective stigma-reduction interventio aiming to improve: (1) physician knowledge of transgender health issues; (2) physician competency to implement transgender-appropriate care; (3) physician willingness to provide quality services; and (4) physician attitudes towards MTF-TG among physicians in Puerto Rico. In order to achieve these objectives, we will implement a mixed method design using qualitative in- depth interviews, focus groups and quantitative questionnaires administered via iPad technology. For aim 1, we will carry out (N = 30) in-depth interviews with physicians who work in HIV-related clinical settings in Puerto Rico. The qualitative information will be used to develop a meaningful understanding of the factors of interest (i.e. knowledge, competency, willingness to treat, and attitudes). For aim 2, we will draw on qualitative data to culturally adapt and pilot tet quantitative measures to assess our variables of interest. We will then administer our survey to a purposive sample of 300 physicians in Puerto Rico, including those who work in HIV-related service delivery and those who do not. Aim 3 will draw on data from focus groups with 30 key personnel from medical schools and medical organizations, as well as 15 MTF-TG recruited by our team's transgender Community Advisory Board, to identify key intervention targets and strategies for reducing stigma and improving access and quality of care. The gathered data will contribute to developing and testing a future intervention that can foster access to quality HIV prevention and health services for MTF-TG in Puerto Rico.